1. Field of the Invention
The invention relates to a holding unit, in particular a toe unit, for safety ski bindings, which has a sole hold-down arranged on a bolt and two angle levers. The angle levers are pivotably mounted about a spindle each, arranged on a supporting member, and being adapted to swivel out to the side against the force of a spring. The sole hold-down is adapted to move upwards against the force of the spring when there is a force acting vertically on it and away from the upper side of the ski (upwards), via a compensating lever, which is designed as a two-armed lever and is mounted to swivel about a bearing spindle arranged on the supporting member. The compensating lever has at least on its one arm two preferably mutually parallel running arm sections, of which each, at least in the descent position of the holding unit, bears against one of the angle levers each either directly or with an intermediate lever interposed. The compensating lever is supported resiliently by its other arm with respect to the sole hold-down and is connected articulatedly to the bolt. The bolt is guided displaceably in the vertical direction, the range of movement of the sole hold-down being limited upwards by a stop, and there being guided displaceably in the longitudinal direction of the ski on the supporting member a wedge element. When the ski boot fitted into the holding unit, the wedge element bears against the ski boot sole. At least one sloping surface of the wedge element interacts with at least one sloping surface of a support part, which is secured against displacement at the bolt supporting the sole hold down.
2. Description of the Related Art
According to Austrian Patent No 372.616, a tie rod is provided, which passes through the supporting member, and acts at one end against the two angle levers and is acted upon at the other end by a spring which can be adjusted in its pretension by means of an adjusting screw.
According to the main patent, in a toe unit, a compensation of the frictional forces additionally occurring during a twisting fall both backwards and forwards on the sole hold-down is ensured. Consequently, a constant releasing force is assured for all possible twisting fall directions.
However, with this solution it was not possible to also initiate the compensation whenever an excessive force loading occurred only in the longitudinal direction of the ski, since the two lateral angle levers were blocked against such a force due to their design. The ski boot sole, in the running position, bore against regions of the individual angle levers running within the two bolts designed as spindles, so that the levers were acted upon by the ski boot sole in the closing direction. Only when a deflection of the one angle lever was initiated and the force component acting in the longitudinal direction of the ski already overcame the blocking angle was a compensation initiated - for example in the event of a forward twisting fall.